Team develops faster method of creating microstructures

Two-photon polymerisation (2PP) is a relatively new additive manufacturing technique (AMT) that is able to fabricate structures with resolutions down to 100nm.

‘As this technique is the first true 3D lithography, it is not necessarily limited to a layer-by-layer fabrication process and it is thus capable of embedding and connecting objects in 3D,’ Jan Torgersen of Vienna University of Technology told The Engineer.

The team starts with liquid resin, which is polymerised at precise points by an fs-pulsed laser (usually emitting at 800nm) leaving behind a line of solid polymer.

In contrast to other AMTs, it is not necessary to prepare the working surface and overhangs can be produced without the need for supporting material.

Previously, the bottleneck of 2PP was the long processing time. To fabricate parts visible without a microscope, several days of structuring was necessary, with typical process speeds of around 100µm/sec.

Using novel photopolymerisable systems and a new mechanical setup, the Vienna team was able to increase this to 5m/sec.